Automatic flue control for furnaces



Dec. 4, 1928.

G.A..TucK

AUTOMATIC FLUE CONTROL FOR FURNACES /NVf/v 70H 6350565 /Z Taf/f @y W@ 2 Sheets-Sheet MIMI Filed Jan. 10. 1927 y lli. il

G. A. rucK l AUTOMATIC FLUE CONTROLFOR FURNACES Dec. 4, 192s. 1,693,769

Filed Jan. 10. 1927 2 Steats-Sheet 2 Patented Dec. 4, 1928.

UNIrEorsTATEs GEORGE A. TUOK, OF sAN FRANCISCO, CALIFORNIA.

AUTOMATIC FLUE CONTROL FORp-FURNAOES..

Applicatioaled January 10, 1927. Serial NO.' 160,107.

within the combustion chamber and fiues of*v the furnace when the fuel is first ignited and 1b 'before the furnace hasbeconie fully heatedf4 This condensation is extremely objectionable,as the nature'of the condensation is such as to veryrapidly corrode the walls and partitions of the furnaceV and greatly shortenthe i 2U life ofthe furnace The primary object of the present invention is therefore to provide an improved furnace having means for preventingl condensation within the furnace.v

Another important problem is to obtain an ing of the furnace. The tortuous'passages commonly provided Within such' furnaces and the ordinary construction 'and arrangement ofthe combustion chambers and iues is such furnace the draft'and circulationisvery poor and as a result the flame is choked and-sometimes entirely extinguished.v lIf the initial draft is made sufficient to Obtainan efficient combustion the draft is subsequently inl creased to such an extent as to greatly reduce the normal operating efficiency. The partial choking of the flame increasesy the condensation within the furnaces above mentioned and is Afurtherl Objectionablefor thatreason. It 'is therefore anotherimportant lobject of the present invention vto provide an improved furnace in which efficient combustion may hey obtained when the fuel is first .ignited and the furnace flue regulating means which is extremely simple in constructionand efficientin operation and which maybe easily Installed.

themost important problems to vbeI improved furnace.

efficient combustion during the initialv heat Ithat when fuelis first ignited within a cold which will'maintain'a `maximum efficiency- A still' further object.v to providean imi' K a I provedv flue regulating means:l which isen- PATENT oFF-ice.

tirely automatic in its operatiOn'and-which maybe casi-ly adjusted to meet the' 'require ments of each particularinstallation,

7 kI accomplishfthese and other objects 'i means ofthe improved device disclosed in the drawings forming a part of the presentapff f plication wherein like characters of reference are used to designate slmilar parts throughf out the specification and drawings, and fin Fig.4 l is a broken-vertical section of the 1 Fig. 2 isa broken sectional detail drawn" upon a larger scale showing thev manneri'inV which air is admitted into "the vcombustion chamber.` i 5 f Fig. 3 is a longitudinalverticalsection of. thevent passage andI flue4 regulating means mounted therein. i 'i Fig. 4 is a longitudinalhorizontal sectionv4 of the ventpgassage and regulating-means as j 'shown in'Fig.y 3.' t

Fig. 5 1s an elevation of theinner end of,V

the membersv` shown in` Figsi and parts f being broken away.

connectionand its damper.

` Fig. 6 is a sectional detail ofthe by-#passi Referring to the drawings theinunieral 1'.

is'used to designate the outer housing shell of a furnace provided'with a combustion chamber 2 having a suitable burner 3 mounted within the bottom thereof andconnected at its upper end witli a tortuous fiuepassage indicated `in generalby the numeral 4. Air

is` supplied around the' burner through* an Y 'air passage 6 formed inthe bottomof the com.-

bustion chamber Q'by meansgof a -partition 7,

the air being` admitted linto ythe combustionv i chamber throughan Opening 84 formed i around the outer side of the combustion.V

chamber.V Air is admitted into the passage 6 through an inlet 9 provided with a pair Aof` doorsr 1l arranged to be moved to 'obtain Y y n desired opening whereby the amount ofrair f admittedmay beregulatedas desired. .The`` fiue passagesl 4 arearrangedl insideof'tlie combustion chamber 2 and. preferablycon-l sist .ofan outer portion 4 and an inner por.;vr

tion 4', the Outer portion 4y communicating:

through passages l13.

f. with the chamber 2.through*passages*p12-and;` communicating with vtheE inner portion 4f,j i.

W w no- A vent ymember `designated in general by" l the numeral 14 is mounted above the comhusf Y eo tion `Chamber 2 and Connected at its inner end diametrically" disposed shaft 22.` A damper' 23 is secured uponthetshlaft 22 and arranged 4 to befmow'ed `to` :fully close the diy-pass 16, one edgeof said damper beingarrang'ed to seat uponv `the]upper edge thea collar` 21 whilethe oppositeedge isarrangedto seat against the' under side of a flange 2&secured upon the top `ot theeollar.

'Thesliaft22 is carried by suitable bear-7V ings formed upon the top of the collar 21.

The innerend of the shaft is extended in-Vv wardly and isprovided `with a. damper 26 ad` -justably secured upon the end of the shia-ft. The d`amper'26 is preferalivly madeof a; plurality of `'overlapping sectors arranged to` be adjusted relative to `Leach `other to obtain a `ipos'itionedin proximate relation to" a partition 271 secured Within the lower portion ofi the vent member 14. The ventfmember 14 isf made of sulieient diameter to permit thefcol-f lar 21 andthe shaft 22 and dampers 23 and" i `26 carried thereby to be inserted "through the outeifendof the member andfitted as a unit upon the top of the by-passlG. 'Flieparv tition 27 reduces' the area` of the passage through the vent member to a desired manif 'lh'eshafti22 and the dempers carried `byare actuated thermostatically by means of a spiral spring 2S formed from suitable metal said springha'ving its innerend secured upon j the i shaft 22 audits outer end secured upon anarml 29 secured upon` the Collarf21,said spring being so designed thatthe expansion i" resulting from heating the spring to a predetermined temperature Willoperzil'te `toE par- Atially rotate the' shaft 22,;and thereby move thodampers'23` and 26into`closing relation with theby-Vpalss 16 andthe opening `-through v theventmember Mpastthe partition 27.k

Infoperation, fthe spring 28 is arranged to *hold the damper 2311i 'fullyopen'position at ordinary room temperatures. VlVlren fuel, die-` 'liveifed' throught-he burner "3, isignited `with- 1n' the combustion chamber,` the Chamber 2" willf b e heated 'almost' at oncle-toits full oper` "ating temperatureand the products of comf` bastion may pass directly `from the chamber 2 Vthrough'the by-fpass 16"- and thencejthrough" ltheventnmrnberlll'to'the chimney `19.` The damper 26fis so adjusted upon the shaft 22 that it ivill bedisposed directly in back of the partition 27 and form no obstruction to the passage through the vent member 14 .past

said partition 27. This permits a maximum draft to beobtained through the flue v portion f i 4 and t so that while the major portion oi the.. products .of combxistion pass j directly through the ley-pass V1b, a relatively small por-V coinbi'isted gases passing directly upwardly through the by-pass 16 to thewhlrnney cause the vent member' lll'and chimney to be quickly y heated to arelatively high teuiperature. At

` the same time; the small amount of combusted Vgas passing through the flue 4, together with the heat radiated from `theel`1ar`nber2, Causes the flue portions 4 and 4' to be gradually heated to aV degree such that condensation y `will not occur. v v

have been raised `to la'ipredetern'lined deemed of temperature, the resultinfrrl expansion ofthe spring -281W1th1n` the mem er 14 causes the shaft 22 tobelrotated'sufficiently to Inovethe A damper "23 intoclosed relationwith V4the loy-` passl. All theproduotsof Combustion must y L nouj'pass through the flue l W-hichiby thistime i desired` "damperarea, said ,damp-er 26 being Willhave.` been heatedto such a (degree that an eilicient draftlwill be produeed, and con` 95 l sage throughthe ventmember Mpast the ai'- `tition 2T,` as shown on the dotted lines in ig.- 5 of thedrawings. The damper 2 6 is 'madeof sectors'relatively adjustable toobtain a. de`` sir-ed areaV1 and the damperzis, also made 'adjustble relative. tothe shaft so `that the move.

' ment impartedby thesliaft 22`:\ vill causo the 'i 'damper-toobstruct a desired `portion of the space above the partition 27 and `theizreby re duce thedraft to a `detfrjee calculated to maine-r 1 tainfa desired chimney or stark temperature and obtain' a mximumheratingefficiency from y ,1101 i and unjust be determined"for eaehf1 partir` lar` installation@@The restrietionfV to 5 the draft `the `fueli Theadjustmentof thednnuper2 is dependent Eupen prevailing `oond1tions` which isfthus obtainedprevents excessivefdi` A* 4. lution l"of the combusted gases by coldl yair drawn Vfromoutside ofthefUrnaCe, and permits the normal draftto bereducedtoa (le-'f` gree adapted` to give/the 'maximum llmatingfV eilit'ieno`y-i The outside'air drawn into "the combustion chamber to maintzfnn combustion is admitted from thejoutsideQo' the burner `through the openings so that suoli air must andbe heatnecessarily cross over the burner ed'heforefpassing into the Hue 4t v Y A y lVhile Ihave illustrated my improved automatie lu'el clcirlrtrol'n as form, in eonnectionwit arfurnacejof one partisular form, the controilfmayof course be a'p pliedto furnacesot various otherty es, and.;v l .i

intended `for use ivith various fuels, w erein it ids is desired to divert the products of combustion from oiie to another of two or more vent y passages to vai? temperature.

the draft and regulate stack therefore, do not wish to restrict myself to the specific furnace construction illustrated nor to theparticular form and cating with the chamber. and fine through openings arranged at spaced points along said chamber and Hue; and means for automaticallyclosing one of said openings and for restricting another opening whenthe temperature of gases within the vent passage reaches a predetermined degree. v

'2. A furnace comprising a combustion chamber and lue;la chimney; a vent passage i connecting the lflue and the chimney; a by#V pass directly connecting the vent passage an d the combustionchamber; and means entirely. enclosed within thevent passage for automat-ically closing the by-pass when the temperature of gases Within the vent passage reaches a predetermined degree.

3. A furnace comprising a. combustion chamber and fine; 'a chimney ;V av vent passage' connecting the flue and the chimney; a, by-

pass connecting the vent. passage and the chamber; means for automatically closing the by-pass when-the temperature of gases within the vent passage reaches ai predetermined degree and means connected tothe by-pass clos- Y ing means and actuated therewith for restricting the passage between the flue and chimney;

4. A` furnace comprising a combustion chamber and flue, a chimney; a vent passage connecting the fiue andthechimney; a bypass connecting the-vent passage and the chamber; means for automatically'closing the by-pass whenthetemperature of v'gases within the vent passage reaches a predetermined degree; and adiustable ineansconnected to the by-pass closing means and actuated therewith for restricting to a. desired degree the passage between the iue and chimney, when the by-Y pass is closed; y

5. A gas furnace comprising a combustionA chamber, a tortuous flue connected to the combustion chamber; chimney; a vent passage connecting the chimney and the 'iiie;.aby-

pass directly. connecting the combustionv chamber and the vent passage.; and means for automatically closing the by-pass by an increase in temperature of gases Within the ventl passage when said temperature reaches apredetermined degree. i Y. Y 6. A gas furnace comprising a combustion chamber; a tortuous fine connected to Vthe combustion chamber; a. chimney; a vent passage connecting vthe chimney and theflue; a

by-pass directly connecting combustion d Chamb er and the vent passage; means enclose-d Within the ventpassagefor a'utomatically clos-Vv ing the by-pass vwhen the teinperature'of gases within the vent passage reaches a predetermined degree; and means connectedtothe bypass closing means and actuated therewith for restricting the passage between` the tine and the chimney.

,7. A gas furnacecomprising a, coiiibust-ion -chamber a. tortuous iue connected to the coin?- bustion chamber; al chimney; a ventpassage connecting the chimney and the flue, a'lby;

pass directly connecting the combustion chainber and the vent passage; `a damper mount- -p ed, in connection with the ley-pass; and lthermostatic means enclosed Iwithin the vent' passage for moving the damper to' closethebyvpass when the temperature of gases within the vent passage reaches a predetermined ,de-

l1 -f .'i .I:

8. gas furnace comprising a icombustion chamber a tortuous flue connected to the'coinbustion chamber; a. chimney; avent passage connectiiigfthechimney and thefiue;aiiiy-passl connecting the combustion chamber andthe vent.k passage; a. damper mounted in connection with the by-pass thermostatic means enclosed within thevent passage for moving the damper to close the by-pass when-the temperature of gases passing through the tortuous flue and the vent passage reaches a predeterl mined'degree; and a vent damper connectedto A the by-pass damperand actuated therewith for restricting the vent passage. when the byf` pass is closed.

9. Aggasfurnace vcomprising a combustion chamber; a, tortuous flue connected to the coiiibustion chamber; la chimney; a vent passage connecting the chimney yand the Hue;

ahy-pass connecting the combustion chamberf and the venty passa-ge; a damper mounted in connection with the bypass; thermostatie iii] y means enclosedwit-hin the vent passage foi" moving. the damper toclose the bypass-when the temperature of gases passing through the tortuous'flue and the vent passage reaches av i predetermined degree; and an vadjustableE 'vent damper connectedto the by-'pass damperl and actuated therewithfor `restricting toa desired degree thevent passage when the bypass is closed. i

10. yIn a. furnace; the combination with a` combustion chamber and fiue of a vent passage having openings.y communicating with said chamber and flue at 'spaced points; a

damper pivotally mounted adjacent one of salid openings; a vent damper connectedjtov the first mentioned damper; and thermostatic vmeans for automatically actuating both damperssimultaneously to closeone opening y and to restrict the vent passage when the temperature v ot gases Within said passage reaches a predetermined degree.`

11. In a furnace .the combination with a eolnbustion'chamber and a` flue of a. vent passage having a main opening communicating with the flue and a. by-V ass opening commu` nicatingV with `the .cham er damperpivet ally mounted adjacent the V4by-paes Opening an adjustable ventdamper mounted within the vent passage and connected With the hypass damper; and thermostatc `means for automatically moving ythe dampers to close the by-passmandrestrlctkthe vent lmssageV when thetemperature of gases Within said vent passagemreaches a predeternnned de- 2.V A gas `:furnace eomprisinga `combustion chamber; atortuous fluelconneeted to the combustion chamber; a chimney;relater-al, vent `passage connecting the iiue andthe chimney; a. by'pass connected directly from i Vthetopofthe combustion chamberinto the closed Within the vent passage-.for automate i ature gases passing outlyardlyfto ,the -chimney reachesa.predetermmct degree. `45` vent. passage; and; means Inountcdiin een` nection with the upper end of the by-ApassV and enclosed Within the yentjpafssage for automatically closing the Vley-pass` and rrestricting the vent passage when the temper- -ature I of 'gafses paesingzoutwardlyg) tothe` clnmney'reaehesa predetermined degree."l

113. A vgas'furnace comprising a comb-usf tion chamber a tortuous ue connected-to` the combustion chamber; chimney; a. lateral Vent' passage connecting `thetlue and the,

ehirnneygeJ ley-pass member Vconnect-ed diT rectly `fromtbe top ofthe combustion chamber into the vent passage, the upper en dV of the Vby-pass member extending .into `theyent passage;` acolilar mounted `upon said upper end of the by-pass member; a. damper mountedV upon thejcollar; and thermostatic means encally elosingtheby-lpass when the `temper- 14. `A furnaceeompi suma combustion chamber; atortuous flueconneeted to thcombustion chamber. Atclifilnney; 'al lateral ventfpassager eonneetlng thcfflue and the chimney; aV bypass `member connected ldu` Y rfen" chamfnl A berinto the ventptissage.,` theupper end Of the l rectly Vfrom thektop of the combus 4lay-pass member extending .into the vent pass-` vage5 a colllarymounted upoirsaad upper end ot' the byepass member; ay damper mounted -upon the collar and thermostatic 4meansenclosed within the' vent? `paf-ezlge' (for.anton]atieally' closing theby-pa-ss when `the temperature Vof gases passingoutwardly' to the? chimney reaches' Va `predetermned degree; and V a L damper mounted Within the vcnttpassage vand actuated 1n connectlontnnth the `by-pass damper for restricting the vent passagewhen y thebypassislclosed. e@

`w15; A gas tur-nace Vcomprising a` fconflbustion chamber; a. tortuous flue connected tothe rent l pas?)age.` connecting;` thene,` and the chimney; al byfpass member connected dicombustion chalnlnn';` al chimney;fa .lateral rect-ly from the top ot' the Con'ibusto'n chan'iber into :theyent passagefthe upper end of the by-pass member extending intoA the vent passage; afcollar removably mounted upon said upper end of the Abyjpass lmember g. la

damper mounted upon Vthe collar; and thermostatlc means Aenclosed within thevent passage andmou'nted in connection with the collar und by-passdamper tor automatieal'ly` 16.; A. gas furnace :eomprisinga combu. f

tion chamber ;'a` tortneus uenconnected tothe combustion chamber;4 a chlmney; a lateral vent passage connectmgf the fluerand, `the edV passage-with chimney; aby-pass member connected di Y rect-ly from the top of the'combustion chamber into the vent pasl'sage5 the upper endet the bypass member extending linto` the -vent Iiassage; a collar removably mounted` upon 'Said upper end of the by-pasemembryu damper vmounted upon thecollar vand ther-3 mostatic means enclosed within the -vent pass-V alge and mounted in connection with the collar and by-pass damperwfor automatica]lyl closing the by-pass when `the temperature ot gases `passing outwardly to thev` chimney reaches a `predetermined deggree, said means being removable from the aient, passage .with

the collar and 4damperyand al@'adjnstableV y dampermounted` in l connection Wi pass damper.` andremofvable therewith `from;A the ventpassagefor restrictingthe lventV pass-3 a gef simultaneously: with` the; closing ot the by-passdamper.

In,A Witnesslwliereofl herelmtofset my sig-f nature. `1

-decadere 

